1. Field of the Invention
The present invention relates to image recording apparatuses that can record images on recording media loaded in trays.
2. Description of the Related Art
Presently, image recording apparatuses that record images on recording media in accordance with input signals are known. Image recording methods used in such image recording apparatuses include, for example, the inkjet recording method and the electrophotographic method.
As recording media on which images are recorded using the above-described image recording apparatuses, highly stiff recording media such as compact discs (CDs) and digital versatile discs (DVDs) have been proposed in addition to recording sheets. In order to record images on highly stiff recording media such as CDs and DVDs, the recording media are typically loaded in dedicated trays. The trays are inserted from disc entrances provided in the image recording apparatuses and transported in the apparatuses. Japanese Unexamined Patent Application Publication No. 2005-59584 discloses an example of such an image recording apparatus.
Typically, whether or not the recording medium is loaded in the tray being transported in the image recording apparatus is determined in accordance with an output value from an optical sensor including a light emitting portion and a light receiving portion in the following method. The light emitting portion emits light toward a region of a surface of the tray in which the recording media cannot be loaded. The light emitted from the light emitting portion is reflected by the surface of the tray and reaches the light receiving portion. The sensor outputs a first output value based on a detection result that is obtained with the light emitting portion and the light receiving portion to a control section of the image recording apparatus.
Then, the light emitting portion emits the light toward a region of a surface of the tray in which the recording media can be loaded. When the recording medium is loaded in the tray, the light emitted from the light emitting portion is reflected by a surface of the recording medium, and reaches the light receiving portion. When the recording medium is not loaded in the tray, the light emitted from the light emitting portion is reflected by the surface of the tray and reaches the light receiving portion. The sensor outputs a second output value based on the detection result that is obtained with the light emitting portion and the light receiving portion to the control section of the image recording apparatus.
Here, the surface of the tray is colored black or the like in order to suppress reflection of light. In contrast, the surface of the recording medium is more likely to reflect light than the surface of the tray is. Thus, when the recording medium is not loaded in the tray, the second output value is substantially the same as the first output value, and when the recording medium is loaded in the tray, the second output value is different from the first output value.
The control section of the image recording apparatus determines whether or not the recording medium is loaded in the tray based on the magnitude of the difference between the first output value and the second output value.